1. Field of the Invention
The present invention is directed to a method for allowing an operator of a magnetic resonance apparatus, such as a magnetic resonance imaging apparatus or a magnetic resonance spectroscopy apparatus, through the operator console for the apparatus.
2. Description of the Prior Art
The pulse sequences utilized in imaging magnetic resonance technology (MRI) and in the magnetic resonance spectroscopy (NMR spectroscopy) are normally parameterizable. Parameters are offered to the operator by means of which the operator selects the anatomy that is of interest (e.g. number, position, orientation of the slices), or influences the contrast between the relevant tissue (e.g. T1/T2 contrast via TR/TE parameters, pre-saturation pulses for fat/water suppression), or selects the resolution depending on the size of the significant objects (e.g. FoV, matrix size, layer thickness), or influences the signal-to-noise ratio of the resulting images (e.g. averages, bandwidth), or controls the measuring time (e.g. TR, TE, concatenations, averages), etc. Generally, the values of these parameters cannot be selected independently of one another. There are numerous dependencies between the individual parameters (for example, TR and the number of the slices), which generally are different for different sequence types. Moreover, the parameter values are subject to further boundary conditions, which, for example, are determined by the efficiency of the utilized hardware (e.g. maximum amplitude and minimum rise time of the gradient system) and the load capability of the patient (e.g. physiological stimulation threshold given rapidly varying magnetic fields).
A difficulty for the dialog system of a MR scanner is to support the user with respect to finding a parameter set (called a protocol), which meets the operator's requirements and which can be implemented with the present hardware.
Conventionally, the user selects a protocol from a set of stored, predetermined protocols, each protocol being optimized for a particular investigation. If parameters must be adapted (normally, this is the case at least for the parameters for selecting the anatomy), only values by means of which the protocol remains intact as a whole, with unchanged values of all other parameters, are offered to the operator/user for each single parameter Pi. The advantage of this approach is that the suitability of the protocols for their intended purpose cannot be degraded by the “over-adjustment” by user. As a result of the aforementioned dependency between the parameters, the value range Ai of the parameter Pi generally depends on the value of the other parameters Pj(j≠i). If the user does not see a desired value offered in the selected protocol, it is theoretically possible to select the desired value subsequent to the modification of one or more other parameters. For this purpose, however, the user needs detailed knowledge about the dependencies between the parameters, which is a disadvantage.